Abstract: A flat plate solar collector (10) of the header/riser type housed in a glazed collector enclosure (14) and having liquid conduits comprising risers (24) intercommunicating with headers (22, 26) at both ends of the risers. The risers are tapered and the headers are surrounded by full heat insulation (28, 30) as defined. The tapering of the risers is effective to prevent bursting of any riser occasioned by freezing of a working liquid especially for example potable water contained therein, by promotion of initial freezing in a localized region of the riser around its minimum cross-sectional area (32) followed by progressive travel of the freezing of the working liquid in the riser in a direction away from the localized region. The full heat insulation is effective to substantially delay total freezing of all the liquid in the headers.

Abstract: A method of applying a liquid coating material to the inside of a tank(10) and performing a hydrostatic pressure test on the tank at the same time. The method is useable for applying a liquid vitreous enamel coating material to a water heater tank, to be subsequently dried and furnace heated to form a glazed enamel internal coating. Preferably the hydrostatic pressure test is performed by displacing coating material from a portion(68) of an accumulator(51) by pumping liquid into a flexible bladder(66) housed in the accumulator. Pressure from pump(76) is transmitted to the tank(10 by the liquid coating material and held for a prescribed time interval to prove tank integrity. The method avoids excessive shear, hence viscosity changes in thixotropic coating materials.

Abstract: The present invention relates to a layered fabric which is a laminate formed from a substrate layer of woven filamentary plastics material and having a first exterior layer of thermoplastic polymer. A second exterior layer of thermoplastic polymer is secured to the substrate, opposite the first exterior layer by means of a hot melt coat positioned in between the substrate and the second exterior layer. The hot melt coat is a thermoplastic polymer. The thermoplastic polymers include polypropylene and polyethylene. Low density polyethylene is preferred. The filamentary material can be a polyolefin, a polyester or nylon but tapes of high density polyethylene are preferred. A method of forming the layered fabric and liquid containment vessels, such as hoses, fabricated from the fabric are also disclosed.

Abstract: The formation of an outwardly extending curl as the upper rim of a pail or drum having a cylindrical wall by curling the peripheral edge through greater than 360.degree. relative to the cylindrical wall forms a strong curl able to support, with the aid of a gasket, a leak proof seal during dangerous goods testing. When used with a lug-cover lid, the lugs may be clenched beneath the curl through a re-entrant portion enhancing the security of the seal. Methods of forming the curl in a two-storage operation by forming primary and then secondary curl components, and an improved lug configuration are also described.